The Americans with Disabilities Act (ADA), which affects many public and private commercial buildings, is intended to ensure equal access to all persons regardless of physical disabilities. Section 309.4 of the ADA accessibility guidelines related to window and door hardware sets forth that “[o]perable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate operable parts shall be 5 pounds (22.2 N) maximum.” The Department of Justice Standards for Accessible Design (4.27.4) and the International Building Code (ANSI 309.4) set forth similar guidelines.
Architects prefer larger vents for exterior window designs to meet fresh air ventilation requirements. Using a larger quantity of smaller vents is typically more expensive than using a fewer quantity of larger vents. Additionally, current energy codes and specifications require low thermal insulating values for windows. Insulated glass has a better insulating value than metal, so the more metal used in a window system, the lower the insulating value. Because the exterior seal of a vent is subject to lower insulating values by nature and is a weak thermal point in the window system, a larger vent size helps to offset the overall insulating value due to the greater percentage of glass. A larger vent helps in the insulating performance but a larger vent takes more force to open.
Although using larger vents may improve insulating performance and decrease costs for architects, larger vents are typically more difficult to open and close. More specifically, an insulated glass unit weighs approximately seven (7) lbs. per square foot and can weigh as much as eight and one half (8.5) lbs. per square foot for insulated laminated glass. When aluminum and other materials are added to construct the vent frame and sash, a vent can weigh around nine (9) lbs. per square foot or more. As such, a four (4) foot by five (5) foot vent may weigh approximately one hundred and eighty-nine (189) lbs. or more, which may be difficult to open using not more than five (5) lbs. of operational force as required by applicable ADA and other guidelines.
In addition to generally being more difficult to open and close, larger vents are also typically more difficult to lock and unlock. Vents, like other window systems, are manufactured and installed to meet strict air and water performance specifications. As such, to compress a sash to a vent frame of the window system, a great deal of compressive force can be needed to make the system air and water tight. The compression of the sash to the vent frame is commonly achieved by the locking of the sash using the vent handle, which moves one or more transmission bars inside a euro-grove (or vent track) around the perimeter of the sash when the vent handle is rotated in one direction as described, for example, in U.S. patent application Ser. No. 14/711,026, by Evensen, filed May 13, 2015, which is incorporated by reference herein in its entirety.
Many current vent designs for exterior windows require in excess of five (5) lbs. of force to open/close a sash. For example, many current vent designs do not use any mechanisms to open/close a sash (e.g., push open and pull closed), which may require more than five (5) lbs. of force, particularly for larger vents. Further, current vent designs that do have mechanisms for opening/closing a sash may not alleviate the force necessary to open/close the sash to meet the ADA guidelines. Instead, some mechanisms, such as cranks, not only may require more force to open, but also require excessive twisting. Additionally, many current vent designs for exterior windows require in excess of five (5) lbs. of force to lock/unlock a sash, particularly for larger vents having locking mechanisms with more locking points. Also, many current vent designs that do have mechanisms for opening/closing a sash use different mechanisms to unlock/lock a sash.
Sections 308.2 and 309.3 of the ADA accessibility guidelines set forth that parts operated by a forward reach that is unobstructed shall be at a minimum fifteen (15) inches and at a maximum forty-eight (48) inches above the finish floor or ground. In situations where the vent handle is located at a side of the vent, as opposed to the bottom, for example, the operation point of existing vent designs may exceed the forty-eight (48) inch operational height requirement. For example, a sixty (60) inch tall vent may be mounted on a twenty-four (24) inch knee wall. The vent handle may be mounted at a side of the vent sash and preferably in the center such that an applied force is distributed evenly. Accordingly, in the above example, the preferable vent handle location would be fifty-four (54) inches above the finish floor, which would be above the maximum operational height requirement.
Moreover, some existing opening/closing and/or locking/unlocking systems may be ineffective or inoperable in confined spaces. For example, longer handles used on systems that pivot ninety (90) to one hundred eighty (180) degrees use a considerable amount of operational space that may interfere with or limit the use of space adjacent to the vent.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.